Houllier said: "I'm disappointed with the result but not with the effort and commitment of the players. I thought we were very good in the first half, we then had a bit of a dip at the start of the second and came strong again towards the end.
"We had chances to equalise, we should have had a penalty, but it wasn't to be for us. The players are down but I told them we have to keep going and keep believing in what we are doing.
"We had to play this game just two days after a match in Romania on a quagmire of a pitch whereas United had an extra couple of days to prepare for it. It's a pity we had to play such a big game so soon after a difficult match away in Europe."
"Despite the results this season I still feel we are making some progress and some improvements. Of course it is going to be difficult for us to win the title now - it's looking like a three horse race for first place - but we'll keep on going and giving our best. We want to make sure we get into that top four."
Listen to Houllier's post-match comments